Nuclear pore complexes and associated proteinaceous lamina isolated from rat liver nuclei will be subfractionated. Antibodies against various polypeptides of the nuclear pore complex - lamina fraction will be used to investigate its cellular physiology. BIBLIOGRAPHIC REFERENCES: A modified procedure for the isolation of a pore complex--lamina fraction from rat liver nuclei. Dwyer, N., and Blobel, G. J. Cell Biol. 70, 581-591, 1976.